1. Field of the Invention
The present invention relates to a fuel cell assembly and a method of producing the same, and more particularly to a fuel cell assembly including a plurality of fuel cells each having a solid electrolyte plate including an oxygen electrode on one side and a fuel electrode on the other side, an electrically conductive flow-channel forming member disposed in opposition to the oxygen electrode for forming an oxygen-bearing gas channel or in opposition to the fuel electrode for forming a fuel gas channel. A plurality of fuel cells are stacked one on another with a predetermined space therebetween for forming the oxygen-bearing gas channel or the fuel gas channel, within which an elastic electrically conductive and gas-porous member is provided for allowing electrical conduction as well as elasticity and gas permeability between the adjacently stacked fuel cells.
2. Description of the Related Art
In the fuel cell assembly of the above-described type, the elastic conductive member is interposed between adjacent cells, with the conductive member being placed in contact, on one side, with the flow-channel forming member of one of the adjacent cells and in contact, on the other side, with the oxygen or fuel electrode of the other cell, thereby to allow electrical conduction between the two cells. During an operation of the fuel cell assembly, there occurs a rise of temperature in the assembly which tends to cause heat distortion or warp of the cell assembly components. Then, the elastic conductive member, by its elasticity, serves to absorb such distortion or warp so as to maintain the good contact, i.e. electric conduction between this conductive member and the channel forming member as well as between the conductive member and the oxygen or fuel electrode. In short, the elastic conductive member functions to maintain good electric conduction between the adjacent cells.
However, with the temperature rise associated with the fuel cell assembly operation, the conductive member loses some of its elasticity. Accordingly, the contact condition between this conductive member and the channel forming member deteriorates to increase frictional resistance between the same. As a result, the electric conduction between the adjacent cells is impaired so that a high internal electric resistance develops within the fuel cell assembly, and such high internal electric resistance necessarily leads to disadvantageous reduction in the power output of the assembly.
The present invention attends to the above-described problem. Therefore, a primary object of this invention is to provide an improved fuel cell assembly and a method of producing the same, which assembly is constantly capable of large power output due to minimized internal electric resistance, the improvement being achieved through ingenious arrangement for the electrically conductive connection between adjacent cells.